Is End to End test is time consuming?

According to one strategy named, Ice cream corn approach, it stated that we have to spend less time in end to end testing and more in unit & api level testing.

Because when we are doing end to end testing then, user clicks or pass data on frontend and frondend calls respective APIS and access backend data. And when we automate this process and at the end it becomes time consuming.

At this point I am partially agree with this approach. Can any one please provide your views and suggestions on this.

Apart from this, solution to handle this kind of approach is, like there are some tool named, "pact" are available that helpful to mock api to test frontend. So my question is is, it good approach to test frondend by mocking api's?